I^IO ON THE NATURK OF OXIMURIATIC ACID. 



flisengaged; but if a little water* be added, very abundant 

 Tapours of the acid immediately arise. The obvious con- 

 clusion from this is, that water is essential to the constitu- 

 tion of the muriatic acid gas. Yet this is avoided by suppos- 

 ing in conformity to Mr. Davy's hypothesis, thdt dry 

 muriate of potash is not a compound of muriatic acid and 

 potash, but of oxirauriatic acid and potassium ; and farther 

 supposing, that the water added is decomposed, its hi- 

 drogeu combining with the oxirauriatic acid, and convert- 

 ing it into muriatic acid, and its oxigen changing the 

 potassium into potash. 

 Indireet argu There are some indirect considerations, however, from 

 extstenceof^ which the existence of combined water in muriatic acid gas 

 -water in the may be inferred, or which at least give probability to such a 

 ^njt muriatic gupposition. Thus it is obvious from the facility with which 

 this acid when in the gaseous state is condensed by water, 

 and from the large quantity of it that is absorbed, that an 

 affinity of considerable strength exifts between them* In 

 consequence of this affinity the acid in its gaseous state 

 must retain a portion of water combined with it; and frpm 

 the law of qhemical attraction so well established, that 

 quantity adds to its force, it follows, that this water M-ill be 

 retained in combination with a strength of attraction pro- 

 gressively increasing as it is abstracted ; and that a portion, 

 therefore, must probably remain, in the driest state to 

 which muriatic acid gas can be brought. 

 Theproba- The supposition, that muriatic acid contains combined 



)nhtyofthJs water, and that this is essential to its gaseous state, is 



saiengthened . 



fey th« analogy rendered more probable by this influence of the coml^matjon 



©f carbonic ^f ^^ter beinsr established with regard to other elastic 

 %CKi sas« 



fluids, where there is not the same ambiguity. Carbonic 



acid cannot be easily expelled by heat, or even by the 



action of an acid, from native carbonate of barytes; while it 



is expelled from the artiticial carbonate with facility ; 



though the only difference between the carbonate in these 



forms is, that in the qne it contains a portion of water, and 



i« the other it appears to contain none. And accordingly, 



if water be appTied to the native carbonate, it favours itsi 



cTecom position, and the expulsion of the carbonic acid. In 



tliii case 18 'clearlj'"' established the influence of water with 



'• ' ' '*^ regard 



